Western Digital Technologies, Inc.

Hgst Netherlands, B.v.

Filip Blagojevic

Cyril Guyot

Zvonimir Z Bandic

Robert Eugeniu Mateescu

Qingbo Wang

Timothy Tsai

Adam Manzanares

Lluis Pamies-Juarez

Yuval Cassuto

Modifying a page stored in a non-volatile storage includes receiving one or more requests to modify data stored in the page with new data. One or more lines are identified in the page that include data to be modified by the one or more requests. The identified one or more lines correspond to one or more respective byte ranges each of a predetermined size in the page. Encoded data is created based on the new data and respective locations of the one or more identified lines in the page. The encoded data is cached, and at least a portion of the cached encoded data is used to rewrite the page in the non-volatile storage to include at least a portion of the new data.

Page modification encoding and caching

Various aspects for managing input/output operations in a storage network are described. For instance, a method may include applying a hash function on a target data object to calculate a hash key for the target data object and identifying a target storage bucket for the target data object based on the hash key and a hash table map. The method may further include reading a data object key for a data object stored in the target storage bucket and comparing the data object key and the hash key to determine a match. The method may also include determining that the data object is the target data object if the data object key and the hash key match and reading the target data object from the target storage bucket when there is a match. Some methods can be performed using a single remote direct access request.

Managing I/O operations in a storage network

Techniques for generating parities and repairing data erasures using a cache oblivious encoding algorithm are disclosed. The system includes an encoding module which receives a request to recreate data for a subset of a plurality of content stores from a storage manager. The encoding module generates a new first parity and a new second parity using the remaining content in the plurality of content stores. The encoding module generates a first portion of the requested data using the new first parity and a first parity for the plurality of content stores and a second portion of the requested data using the new second parity and a second parity for the plurality of content stores. The encoding module may recreate the data for the plurality of content stores using the first portion of the requested data and the second portion of the requested data.

Cache oblivious algorithm for butterfly code

Approaches for retrieving files from a replicated file system. A component receives, from a requestor, a request for a copy of a data unit. The component identifies a plurality of storage nodes that each stores a complete copy of the data unit. The component sends, to the plurality of storage nodes, an instruction to retrieve a copy of the data unit within a specified period of time. At each storage node receiving an instruction, a determination of whether the copy of the data unit may be retrieved within the specified period of time is made, and if so, the copy of the data unit is provided to the component only if the copy of the data unit was actually retrieved within the specified period. The component provides the first copy of the data unit it receives to the requestor and discards any subsequently received copies of the data unit.

Growing community of inventors

Emeryville, CA, United States of America

Filip Blagojevic